We did something kinda similar, but it was only two months, not a full year.
My wife and I backpacked through Western Europe for two months prior to our beginning to start having children (Now, a year later we just had our first child)
Back then we decided to just go foward with planning and force our employers to give us that two months off, no matter the career cost. We so DO NOT regret that.
Looking back there are so very few opportunities in our lives to take that dream adventure vacation involving several months or more. Often you just have to make the opportunity in your life to do it.
My only regret? We should have instead taken off SIX MONTHS traveling through Europe!
Our favorite memory of travling in Western Europe?